Air conditioning system

ABSTRACT

The present invention is directed to a practical system for providing year around air conditioning for a manufacturing plant wherein large quantities of air must be exhausted, approximately one-half of which is contaminated with a solid contaminant and one-half of which is contaminated with a fumous contaminant, said portions being exhausted from diverse manufacturing areas. Such contaminated air can neither be recirculated within the area from which it is exhausted, nor can it be used in another area without further treatment. The plant according to the present invention may be heated in the winter and cooled in the summer by a single refrigeration/heating unit which operates much more efficiently than heretofore by the utilization of a heat reclaiming device whereby the incoming air is precooled by the exhaust air in the summer and preheated by the exhaust air in the winter. In addition, the system is enhanced by a cyclone-type dust collector including a rotary drum filter therein which effectively removes the solid contaminants from the air stream and reintroduces the cleansed air for recirculation.

United States Patent [mentor-5 wmiam swckffll'd; Primary ExaminerCharlesSukalo Joseph M- Gam w ll, S li ury. N Attorney-Hunt, Heard & Rhodes[2l] Appl. No. 827,455 [22] Filed Apr. 25, 1969 Patented Jan. 19, 1971 IABSTRACT: The present invention is directed to a practical [73] AssigneeGamewell Mechanical, Inc. system for providing year around airconditioning for a manu- Salisbury. N.C. facturing plant wherein largequantities of air must be exacorporation of North Carolina hausted,approximately one-half of which is contaminated with a fumouscontaminant, said portions being exhausted from diverse manufacturingareas. Such contaminated 54 AIR CONDITIONING SYSTEM air can neither berecirculated within the area from which 14 Claims, 10 Drawing Figs. itis exhausted nor can it be used in another area without furthertreatment- .Tbe elem ms #19151? .thsters sm [52] U.S.Cl 165/3, inventionmay be heated in the winter and cooled in the 165/66 165/1 summer by asingle refrigeration/heating unit which operates [51] Int. Cl F24f 3/ 14h more ffi l than heretofore by the utilization of a held of Search165/3 heat reclaiming device whereby the incoming air is precooled 1 19by the exhaust air in the summer and preheated by the exhaust air in thewinter. In addition, the system is enhanced by a [56] References cuedcyclone-type dust collector including a rotary drum filter UNITED STATESPATENTS therein which effectivel removes the solid contaminants from y2,542,763 2/1951 Frlsk 165/3 the air stream and reintroduces thecleansed air for recircula- 2,862,434 12/1958 Edwards. 165/66 tion.

IOF

l2 |o'- l l' 4* roer l l l l l 4 l3' a 7 O O 14; 0 F 5 l9' F+5% W7 LLLLJl l6'- :7 F 23 PAT-ENTED JAN 1 s IBTI JOSEPH M. GAMEWELL BY WILLIAM F.STOCKFORD Ami 54 44 TTORNEYS I PATENTEUJAM 9 Ian SHEET 2 (IF 5 ,FIG. 4

ATTORNEYS WILLIAM F. STOCKFORD PATENTED Jm'jl 9197i sum 3 or 5 INCOMINGAIR INVENTORE JOSEPH M.GAMEWELL WILLIAM F. STOCKFORD ATTORNEYS PATENTEDJAN] 91971 3; 556; 202

sum 1 OF 5 308 Ml I M III III lflf Kip/r J [I]; 1 W

INVENTOR5 JOSEPH M. GAMEWELL WILLIAM F. ST V I ATTORNEYS KFORD from onearea to precool or preheat the incoming air,

A IR, conmrromno svsrsM' ancxonounoor rnii DISCLOSUR a lnrecent years,industrial psychologists" have found it in. creasingly, more importantto maintain comfortableworking videdinto several-distinct areas in whichthe heating and humidity requirements differ noticeably. or where themanufacwring processes release relatively-large quantities ofcontaminants into the air which prevents its recirculation or'circulation into anothera'rea;

. For example. in the furniture industry} itis customary to have awoodworking area completely separate from the painting or finishingarea. It. is. not possible to circulate the air through thewoodworkingarea and then into the painting or finishing area, because ofthe fine dust and other'wood parti cles which are released into theairin the woodworking area as a resultof the sanding and other woodshaping processes. On

large volume of exhaust air, approximately one-half of which contains asolid contaminant and approximately one-half of which contains a fumouscontaminant including a single heating/cooling unit of a smaller sizethan would be required if both areas were heated and cooledindividually. It is yet another object of this invention to provide abalanced year aroundair-conditioning system for controlling thetemperature and humidity in a manufacturing plant rcquir ing a'largevolume of exhaust air. approximately one-half of which contains a solidcontaminant and approximately onehalf of which contains a fumouscontaminant, said portions of air being exhausted from two separateareas of the plant wherein thc air containing the solidcontaminantswhich is exhausted from the first area is so t eated as to be usable inheating or cooling the second area. s

It is still another object ot this invention to provide a balanced yeararound air-conditioning system for a manufacthe other hand. it is'fnotdesirable to utilize the exhaust air Y because of thefumes'which arepresent in the exhaust air as a result of the painting and finishingoperations, a

' from the painting and finishing area anywhere in the plant;

Both of th se areas require a rapid exh" ust of large jq'uantb ties ofth'e airto reniovethe contaminants ,from thezareas in to provideabalanced year around ,airconditioning system of which peopleareworlting. Since the's'ame amount of air being a exhausted mustbereturned to the plant as makeup air, the ob vious solution would be toprovide eacharea with'its own air conditioning and. heatingyconnectedwith the makeup air ystem- This proves to befalmost prohibitivelycostlyindeed in compfl i n to a system in which only oneairconditioni'ng and heating unit is required. Moreover. it has beenfound during periods of extreme outside temperature such as in midsummeror midwintenthe operation of the air conditioner or heating unit mightbeaided by utilizing the contaminated exhaust air s n-rm or ins inventionturing plant requiring a large volume-of exhaust air, approximatelyone-half of which contains a solid contaminant and approximatelyonerhalfof which contains a fumous contaminant, said portion of airbeing exhausted from two separate areas of the plant; wherein thecontaminated air exhausted from the second operating area is utilized topretreat the incoming atmospheric air so that the system operates moreeconomically. I a i It is yet a further and more specific object of thisinvention theftype described above wherein a heat reclaiming unitreceives contami' 'ted air exhausted from the second manufacturing areaand transfers the heat into or absorbs the heat from the incoming airwithout any aetual mixing of the two bodies of air.-

A further objectof the invention is to provide a balanced year'aroundair-conditioning system of the type described above utilizing acyclone-type dust collector having a selfcleaning, permanent rotary drumfilter mounted therein for receiving and cleaning air containing solidcontaminants from *The present inventioni' on'the other hand. provides asingle heating/cooling unit which provides coolant in the summer whichisused; first of all inthe woodworkingarea and then is painting area.This air is then passed through a standard washer toevaporatively coolthe air and to further remove any wood particles or odors which mightnot be removed in the filter unit. A further feature reclaimer whichreceives the exhaust air from the painting or of the invention is theuse of a heat filtered and circulatedthrough the paintingarea. Acyclonefinishing area at a moderate temperature and passes the ex 7haust air in thermal conductive relati n with the incoming atr mosphericair. Such a processprecools the incoming air in the summer and preheat:the incoming air in thewinter. before it is delivered to theheating/cooling unit, providing a more economical operation since theincoming atmospheric air does not have to undergo as much'of a change intemperature asotherwiseinthecase. Y

It is therefore an object of this invention to provide a practical yeararound air'conditioningsystem controlling ter'nperature and humidity ina manufacturing plant requiring a largev volume of exhaustair.approximatelyione-half of which contains a solid contaminant andapproximately one-half. of which contains a fumous contaminant, saidportions being exhausted from diverse ar'eas of manufacture. r

V d It is another object or this invention to provide a balanced yeararound air-conditioning system for controlling the temperature andhumidity a manufacturing plant requiring a one of themanufacturing areasto such an extent. that the filtered air may be usedin the other area.

Soineof the objects of, the invention having been stated,

other objects will appear as'the description proceeds when taken" inconnection with the accompanying drawings, in

and heating fluid in the winter to a makeup unit, the output of i w aFIG. 1 is a schematic representation of a standard makeup and exhaustsystem showing the-normal temperature and humidity levels during summeroperation;-

FIG. 2 is a'sche'matic representation similar to F [6.- 1, exceptshowing the winter operatipn;

FIG. 3 is a schematic representation of the air-conditioning systemaccording to the present invention, and showing the normal temperatureand humidity levels'during summer operation;

cept showing the w nter operation;

FIG. 4 is a schematic representation similar to FIG. 3, ex-

FIG. 5 is a perspective view of the heat transfer module of the heatreclaimer according to the present invention;

FIG. 6 is an enlarged perspective view with parts broken away, showing aportion of one of the support channels used to separate the layers ofthe heat transfer module;

7 FIG. 7 is a perspective view of one of the plates which forms onelayer of the heat transfer module shown in FIG. 5; v

' FIG, 8 is a perspective view showing the cyclone dust collector usedin the present system;

FIG. 9 is a vertical sectional view showing the automatic drum filtermounted inside the collector with certain parts not shown in section forthe purposes of clarity; and

FIG. 10 is a view taken substantially along line 10-10 in FIG. 9. d

, Referring now to the drawings, and more particularly to FIGS. 1 and 2,there is showna standard makeup and exhaust system according to previousdesigns.

As shown in FIG. I. there is generally no air conditioning orrefrigeration provided at the input of atmospheric air at such plantsduring summer months, because the tremendous ventilation requirements ofthe dust collection system and the paint booth exhaust system normallymake the size of the cooling unit prohibitive and economically notfeasible. Therefore, in existing furniture plants, for example, wherethe outside temperature was 95 F., the atmospheric air is drawn into theplant through a makeup unit with no change whatsoever, except possibly afiltering operation through filter 12. The air is then introduced intothe woodworking area 14, where, because of the activity taking place,the temperature rises to approximately 1 F. and a humidity ofapproximate ly 30 percent. The air is then drawn by fan 17 over thevarious woodworking machines and through a conduit l6whereupon it isdelivered to some sort of filter, such as a cyclone dust collector 18which deposits the dirt and dust particles in the bottom thereof andallows the filtered air to escape to the atmosphere through the top. Atthe same time a second makeup unit receives air from the atmosphere,passes it through filter 22 whereupon it is supplied to the painting orfinishing area 26 through conduit 24. The operations in the painting orfinishing area cause the temperature to rise to approximately 105 F. anda humidity of approximately 35 percent, whereupon it is exhausteddirectly to the atmosphere after absorbing overspray and drying fumes.

FIG. 2 illustrates the operation of a typical prior system during thewinter, and for purposes of explanation, it is assumed that the incomingtemperature is approximately 10 F. Makeup unit 10' comprises a filter12' through which the incoming air passes and some appropriate heatingdevice such as a pair of heating coils 11 and 15 which are connectedwith boiler 19' or other source of heat. As the atmospheric air passesover the coils, it is elevated to at least a temperature of 50 F. beforeentering the woodworking area 14' through conduit 13'.

The lights and activity in area 14 generally cause the temperature to befurther elevated to as much as 70 F. with relative humidities as low as'5 percent. This air is collected and drawn into conduit 16 by fan 17'and filtered through some type of filter such as cyclone filter 18whereupon it is exhausted to the atmosphere at a temperature ofapproximately 75 F. It can readily be seen that if this air beingexhausted to the atmosphere at 75 F. could be recirculated or routedthrough some other area, there could be a significant saving in the costof heating, however this air is contaminated by the sawdust and otherfine particles entrapped in the air in the woodworking area and cannotbe reused.

In the finishing or painting area 26' of the plant, a second makeup unit20 includes an appropriate heating device such as a pair of heatingcoils 21' and 23 connected with boiler 19 or other heating media. Theincoming atmospheric air passes through filter 22' and then over coils21 and 23' containing steam or hot water, whereupon the air is warmed toa temperature of at least 60 F. before being delivered into the paintingarea 26' through conduit 24'. In the painting area the temperature risesto approximately 70 F. with a relative humidity as low as 5 percent,whereupon it is exhausted to the atmosphere through the paint booths.

HEAT SAVER SYSTEM Turning now to FIGS. 3 and 4, the summer and wintersystems respectively, according to the present invention, are shown. InFIG. 3, it is assumed that the same atmospheric temperature of 95 F.prevails for purposes of this discussion as was the case in thediscussion of FIG. 1. Heat exchanger 200 is of the air-to-air type whichfirst receives the atmospheric air and precools it to a temperature ofapproximately 85 F. before delivering it to conduit 1 16. Heat exchanger200 adds no mechanical refrigeration to the atmospheric temperature,rather subjects the atmospheric air to a thermal engagement with theexhaust air leaving the painting area and evaporatively cooled withwater to a temperature of approximately 70 F. This stage precools theatmospheric air, so that the makeup also has mounted therein a spraycoil unit 112 which circulates cooling media from compressor 122 overwhich the air passes. Water sprayed from nozzles 114 onto conduit 116and/or housing 113 evaporates into the airstream, thereby providing asource of humidity control for the woodworking area 128. This improvesthe efficiency of all the woodworking operations and improves the finalquality of the product by maintaining a relatively constant woodmoisture content year around.

A smaller conduit or pipe 118 circulates the refrigerant or coolingmedia from the heat rejection or condenser coil 119 to the cooling coil112 whereupon it is returned through pipe 120 to compressor 122. Therefrigerant is then put under pressure and fed to the condenser coil 119where it is condensed into liquid form. It then passes to pipe 118, backto spray coil 1 12 whereupon the cycle is completed.

To further increase the efficiency of makeup unit 110, the relativelycool air being exhausted from the paint booths, after passing throughthe heat reclaimer, passes through the heat rejection device 126 whereipthe heat picked up by the cooling media in spray coil 1 12 and presentin coil 119 is removed and discharged into the atmosphere. I

The combined effect of the heat exchanger Y200 and mechanical makeupunit 110 lowers the temperature of the air leaving makeup unit 110through conduit 126 to a temperature of approximately F. whereupon it isintroduced into the woodworking area 128. The operations in thewoodworking area 128 elevate the temperature to approximately F. andlower the relative humidity to approximately 50 percent. Sawdust andother fine dust particles present in the woodworking area contaminatethe air and make it unsatisfactory for subsequent use in that condition.

The contaminated air is collected in the dust collection system bycollector fan 131 which draws the air into conduit 130, whereupon it isdelivered to a unique type of cyclone dust collector 132 including apermanent, self-cleaning rotary.

drum filter mounted therein as illustrated in FIGS. 810 and hereinafterdescribed to thoroughly cleanse the air. For the purposes of the presentdiscussion it is sufficient to note that the sawdust and othercontaminating particles are completely removed from the air in collector132, so that the filtered air is pure enough to be reused, however thecollection process elevates the temperature somewhat to approximately F.This air is carried by conduit 134 to an air washer in which the air issubjected to a spray to lower the temperature, pick up moisture content,and remove any solid contaminants or odors which may bypass the dustcollector 132 before exiting through a set of eliminator blades whichremove the excess moisture from the air. This saturated air atapproximately 75 F. is subsequently carried through conduit 142 andintroduced into the painting or finishing area 146.

In the painting or finishing area, the air increases in temperature toapproximately 85 F. with a relative humidity of at most 60 percent andpicks up flammable paint fumes, whereu pon it is drawn from the areainto conduit 148 by exhaust fans. During summer months, this exhaust airis subjected to a nonrecirculated water spray 149 which decreases thetemperature to approximately 70 F. This air then passes through the heatreclaimer 200 in thermal contact with the incoming air in a mannerdescribed below, which subsequently transfers heat from the incoming airlowering it to a temperature of approximately 85 F. The exhaust air thenexits from heat reclaimer 200 through conduit 150 at a temperature of 80F., passing through the heat rejection device 126 and picking up heatfrom coil 119 therein before exiting at a temperature of approximately115 F.

Referring nowto FIG. 4, the winter'operation of the heat saver systemfollows generally the same cycle as that described above, however heatexchanger 200 producesan opposite effect on the incoming air Morespecifically, the incoming air is preheated approximately 30 by theexhaust air, so that the mechanical makeup unit of the system does nothave to supply as much heat as would be the case if the incom ing aircame directly into the makeup unit.

Assume the incoming atmospheric air to be at a temperature of F- as itpasses through heat exchanger 200 it picks up heat fromthe exhaust airleaving the painting area at approximately 75 F. by nature of thethermalengagement in the heat exchanger, with theresult that theincoming air is heated approximately 30 to aitemperature ofapproximately 40 F. before delivered to'conduit I16. Nozzle I14 sprayswater on the coil-housing 113 to control the humidity of the air as itpasses therethrough. The mechanical refrigeration system is reversed toadd heat into the incoming air. and a warming media ispassed throughspray coil 112 to heat the incoming air to a minimum temperature ofapproximately 50 F.

. In winter operations. coil 119 receives the refrigerant from coil 112through pipe 118. The refrigerant gas'is pulled from coil 119 by.compressor, 122 through pipe 124 whereupon it is compressed anddelivered to coil 112 through pipe 120 towarm the incoming air. It isreadily apparent that this is merely the reverse of the summer operationof-the cooling device. Exhaustair from paintingarea 146 leaving the heatexchanger 200 passes over coil 119 and adds heat, into the cooledrefrigerants!) that it is warmer and aids'in boiling off the gasincoilll9. 7

It is to be recognized that the reversible compressor system illustratedandv described is only an example of oneof many would be necessary forthe painting area. which would in crease substantially the cost of thesystem.

HEAT RECLAIMING DEVICE Heat reclaimer 200. referred to above. comprisesessentially a seriesof light-gauge metal plates 204 and 206 stacked inalternating arrangement. having stiffeners and separators 208therebetween as required, the assembly being so arranged that incomingatmospheric air entering one side thereof is in thermal engagement withexhaust air entering an adjacent side, however is isolated from actualmixture therewith.

Plate 204. as shownin FIG. 7 is formed of a relatively lightweight metalmaterial having good thermal conductivity and comprises a flatrectangular body portion 210 having upturned sidewalls 212 and 214andi'downturned end walls 216 and 218. Plate 206 is similar to plate204, except having downturned sidewalls 220 and 222 and upturned endwalls 224 and 226. As best seen in FIG. 7, plates 204 and 206 are soassembled that the upturned sidewalls 212 and 214 of plate 204 overlythe downturned sidewalls 220 and 222, and the downturned end walls 216and 2l8overly upturned end walls 224 and 226. The overlapping side andend walls may be joined by any suitable means, as by rivets 246.Additional plates 204 and- 206 are alternately assembled as shown in-FIG.

' 5 forming an assembly having alternating passageways 228 types ofheating/cooling systems that could be used with the present invention.Othersystems include a fumace/refrigeration compressor, a furnace/waterchilling unit. etc.

The heated air at a temperature of 50 is delivered into the woodworkingarea 128 through conduit 126, and in area 128, asin the case during thesummer. the lights and activity therein elevate the temperature toapproximately 70 F. and a relative humidity "of at least 40 percent, Thecontaminated air is drawn from the woodworking area by fan 131through'conduit I30 and again is subjected to the unique cyclone dustcollector which cleanses the air, so that it may be reusedin thepainting area. The air leaves the dust collector 132 through temperatureof theair to approximately 65 F. for delivery to the finishing orpainting area 146through conduit 142.

In the painting area 146 the temperature of the air is elevated to 75 F.and arelative humidity of at least 45 percent, whereupon it is exhaustedand delivered into conduit 148 at a temperature of approximately 75 F.

This exhaust air includes paint fumes, so that it may not bereintroduced into the woodworking area; however, as described above, hispassed through the heat reclaimer in thermalengagement with theincomingair, causing the incoming air to rise 30fin temperature. Theexhaust air gives up a substantial portion of heat to the incoming air,and is thus exhausted into conduit 150 at a temperature of approximately45 F. Conduit 150; in turn delivers the air to evaporator 126 where itpasses over coil 119 adding heat to the refrigerant as earlierdescribed. Z i a Since it is only necessary for the'cooling/heating unit122 to lower the temperature 20in the summer and to raise thetemperature of the air leaving theheat exchanger approximately 10 in thewinter, it becomes apparent that a smaller heating/cooling unit than isused in a 100 percent makeup unit may be used. Moreover, because of theunique cyclone dust collector, the air leaving the woodworking area maybe reused in the painting area by merely subjecting it to an air washerto control the humidity in the painting area. Otherwise, a completely.separate mechanical refrigeration makeup unit and 230 perpendicular toeach other. The assembly is covered by a flat plate cover 202.

The incoming atmospheric air enters passageways 228 in the direction ofarrow B while the exhaust air enters passageways 230 in the direction ofarrowA in FIG. 5. The incoming air is precooled or preheated bytheexhaust air which is in thermal engagement through thin plates 204 and206, however, the two air" masses never actually mix with each othersince the exhaust air is contaminated with paint fumes.

Spacers 232 separate plates 204 and 206 and provide support forretaining the plates in spaced relation. As best seen in FIG. 6, spacers232 comprise a channel member having a web 234 connecting upper leg 236and lower leg 238. Strips of resilient material 240 and 242 are suitablyattached to the outer surface of legs 236 and 238 respectively to dampenvibrations caused by the air masses passing through passageways 228 and230 in the heat exchanger and to seal the alternate chambers from airleakage.

It should be recognized that the specific structure of the abovedescribed heat exchanger is for the purpose of explanation only, and itshould be realizedtha't various changes to the assembly and'supporttechniques herein described could be made without departing from thescope of the invention.

CYCLONE'DUST COLLECTOR Referring to FIGS. 8 and 9. there is illustrateda specific embodiment of the cyclone dust collector 132 referred to inthe heat saving system described above. Dust collector 132 from theoutside resembles a conventional cyclone-type collector in use today andcomprises a housing 300 having a cylindrical upper portion 302 and aconical lower portion 304. An opening 306 in one side of cylindricalportion 302 receives conduit and provides an inletfor the air leavingthe woodworking area. Housing 300 further includes an inverteddish-shaped cover 308 open in the center and having an upstanding wall309 around said opening to which conduit 310 is attached, providing anoutlet for the filtered air.

The contaminated incoming air enters the collector 132 through inlet 306and swirls round and round in cyclone fashion inside the collector. Thedust. particles suspended in the air are forced to the outside walls bycentrifugal force, whereupon they fall down onto the conical walls ofthe lower housing portion 304 and drop through opening 312 in thebottom. The filtered air, on the other hand. exits the collector throughthe opening in cover 308 and is delivered into conduit 310 for useelsewhere or is released to the atmosphere. The structure described sofar is conventional in industrial application today and merely providesa background for the specific structure mounted within and describedbelow.

Turning now to FIG. 9, a self-cleaning, rotary drum filter 330 issuspended within housing 300 from an outwardly extending annular flange312 attached to the upper end of cover 308. Flange 312 supports asimilar annular flange 314 extending outwardly from collar 316 which inturn connects conduit 310 with cylindrical housing 318. Housing 318 fitssnugly against the inner surface of upstanding wall 309 and extends downinside housing 300 to support filter 330. The upper end of housing 318is completely open to allow passage of air, however the floor 320 ofhousing 318, although generally open, includes a skeletonlike framework(FIG. 10) to provide a mounting surface for the filter controls. Shaft322 is jour naled for rotational movement between upper support 320 andlower support 324, both supports being stationary. Several peripheralbraces 326 extend between upper support 320 and lower support 324 toretain the support members in their fixed spaced relation.

Several supporting spokes 332, 334, and 336 are fixedly attached tocentral rotating shaft 322 for rotation therewith. A first or innerlayer 338 of relatively coarse screen is stretched around the peripheryof the spokes, and a second layer 340 of finer mesh filter media is laidon the outer surface of screen 338, thus forming a rotatable cylindricalfilter.

A suction nozzle 342 is suitably fixed to upper and lower supports 320and 324 and extends'longitudinally along the surface of filter media340, being stationary with respect to the filter 330 which rotates. Alength of flexible hose 344 including a suction fan 34S connects thelower end of nozzle 342 with lower opening 312 and provides a conduitfor exhausting the sawdust and other dust particles drawn from thesurface of filter media 338.

Rotary drum filters mounted within cyclone-type dust collectors are inthemselves old as shown by the U.S. Letters Patent to Hershey, Jr., No.2,827,128. This patent even teaches the use of a pressure sensitiveswitch arrangement for turning the rotating cleaning nozzle on and off.The present invention, on the other hand, utilizes a stationarycontinuous cleaner, rather than a rotating cleaner, that starts andshuts off in response to the pressure differential between thehigh-pressure and low-pressure sides of the filter media.

A variable speed drive mechanism comprising a motor 346 and speedreducer 348 of the type commercially available, as for example theGraham variable speed ball/disc drive, is mounted within housing 318 onupper support 320. Rotating shaft 322 is connected to the output of thespeed reducer 348, thus providing the rotary force necessary to turn thefilter media in response to pressure variations between the air outsideand inside the drum filter 330.

A pressure sensing device or pressure regulator 350 includes a firstpressure sensing nozzle 352 in communication with the air outside thefilter media, and a second pressure sensing nozzle 354 in communicationwith the area inside the filter media. When the pressure differentiationbetween the two sides of the filter media reaches a predetermined level,the pressure regulator 350 signals the motor 346 which operates thevariable speed device 348 through pneumatic line 356, thereby adjustingthe rotational speed of the filter media.

The reason for adjusting or varying the speed at which the drum filter330 rotates is that the filter media 340 is of the surface loading typeand comprises wire mesh upon which the dust particles are deposited.This results in a buildup of dust particles on the surface thereofenhancing the filtering effect. If the filter is kept perfectly clean atall times, some of the smaller dust particles will pass through, and onthe other hand, if the media becomes laden with too much dirt, the airwill not pass through at all. Therefore, it is important to note that aslightly dirty filter is a good filter, and a delicate balance must bekept. The idea is to move the filter media at a given speed past thesuction cleaner only fast enough to keep the filter in a desirably dirtycondition.

CONCLUSION Thus, there is provided a year around air-conditioning systemwhich will provide a comfortable temperature and humidity level at alltimes, resulting in a cleaner more desirable atmosphere in which towork. ln certain industries, such as the woodworking industry, it ishighly desirable to maintain the humidity level within prescribed inorder to obtain the highest quality of furniture manufacturing. Yeararound temperature control increases the productivity ofemployees, andthe continuing hange of air provided by the ventilation system describedherein prevents the build up of flammable vapors from the painting area.

Although specific temperature andhumidity ranges have been set forth asdesirable in the above description, it is to be realized that thesetemperatures and humidity percentages are for purposes of explanationonly, and the invention is not limited to such specific ranges, the ideabeing to beable to control temperature and humidity. Moreover, thespecification specifically describes a system for a furniture manufacturing plant comprising a woodworking area and a painting or finishingarea. It is to be realized that this type of system may be used in anytype of manufacturing in which there are two areas in which diversemanufacturing operations are being carried on prohibiting the direct useof air from one area in the other area. Moreover, the system describedabove permits the controlled temperature and humidity levels throughoutthe year in a much more economical and feasible setup than heretofore inuse.

Therefore, although a detailed disclosure has been made of a preferredform of the present invention, it will be understood that modificationsand variations of the-suggested form may be resorted to, while remainingwithin the scope of the present invention.

We claim: I

l. A method of providing year around air conditioning for amanufacturing plant having a first and second area wherein diversemanufacturing operations are being carried on with consequent diverseeffects on the temperature and or humidity and cleanliness of the airwithin said first and second areas, and wherein relatively large volumesof air are circulated, approximately one-half by volume of thecirculated air being exhausted from said first area and containing solidcontaminants and approximately one-half of the circulated air beingexhausted from said second area and containing fumous conincoming air isprecooled in the summer and preheated in the winter; c. Delivering saidincoming pretreated atmospheric air to said first area and contaminatingit with solid particles;

(1. thereafter exhausting the solid contaminated air from said firstarea and cleansing it of said solid particles;

e. delivering the cleansed air to said second area and contaminating itwith fumes; f. thereafter exhausting the fumous contaminated air fromsaid second area and delivering it into thermal engage step (b) saidpretreated incoming air is further subjected to a mechanical heatingoperation in the winter and a mechanical cooling operation in thesummer, said heating and cooling operation further includes subjectingsaid incoming air to a washing operation wherein said air becomessaturated prior to delivery to said first area.

coil to the air in the summef operation.

thetemperatureis lowered and the humidity is elevated to a prescribedlevel.- a i i 5. The method according to claim "I wherein during thesummer months. the fumous contaminated air exhausted from the secondareais subjected to' a water spray prior to step (f) 1 thereby loweringthe temperatureofthe air prior to its thermal engagement with saidincoming air, so that the incoming air is precooled to an even greaterextent. r i 1 6. A temperature and humidity control for use in amanufacturing plant having afirstand secondarea in which diversemanufacturing operations are I being carried on with consequent diverseeffects on the temperature and or humidity and cleanliness of the airwithin said first and second areas, and wherein relatively large volumesof air are circulated, ap proximately one-half by volume of thecirculated air being exhausted from said first area and containing solidcontaminants and approximately one-half of the circulated air beingexhausted from said second area and containing fumous contaminants, saidsystem comprising: i a

a. a makeup unit including a means for drawing in the outside air intosaid system and delivering it to said first area; b. a heatexchangerpositioned in said system between the intake of said outside air andsaid makeup unit, said heat exchanger including a first meansfor'passing said incoming air therethrough, said heat exchanger furtherincluding a second means for passing the fumous contaminated airexhausted from said second area therethrough. said first and secondmeans being separated by a wall of heat conductive material, wherebyheat is transferred between said incoming air and said fumouscontaminated air while preventing actual mixing of the air masses;

c. 'a dust collector positioned in the system between said first andsecond areas and receiving the solid contaminated air exhausted fromsaid first area, said dust .collector including a means thereinfor'separating the solid particles present in said solid contaminatedair from the clean air in preparation for the delivery of the cleansedair to said second area; and a d. means connecting said heat reclaime'r,makeup unit, and said dust collector with said firstand second areas forproviding an airflow path through said system.

7. The temperature and humidity control system according to claim 6wherein said first means in said'heat exchanger comprises a first set ofpassageways therethrough in one direction through which the incoming airpasses and said second means in said heat exchanger comprises a secondset of passagewaysextending transversely to and in alternating relationwith said first set of passageways through which said fumouscontaminated air passes. said first and second passageways beingseparated by a relatively thin sheet of heat conductive material.

8. The temperature and humidity. control system according to claim 7wherein said first and second passageways-include at least one supportmember extending between and in engagement with adjacent surfaces ofsaid thin sheets of heat conductive material, said supports including astrip of vibration absorbing material attached to the surfaces of saidsupport which engage said thin sheets.

9. The temperature and humidity control system according to claim 6wherein ,said makeup unit further comprises a mechanical heating/oolingunit for cooling said incoming air in summer months and heating saidincoming air in the winter months.

10. The temperature and humidity control system according to claim 9wherein said heating/cooling unit further comprising a compressor, aspray coil connected to one side of said compressor and over which saidincoming air passes, said coil receiving cooling media in the summer andheating media in the winter, acondenser coil connecting said spray coiland the other side of said compressor.

1 l. The temperature and humidity control system according to claim 10wherein said spray coil is enclosed within a housing through which saidincoming air passes, said housing including a means for increasing themoisture content of said incoming air.

12. The temperature and humidity control system according to claim 10wherein said condenser coil is enclosed in a housing through which thefumous contaminated air leaving said heat exchanger passes, wherebyheat. is transferred between the condenser coil and the air passingtherethrough.

13. The temperature and humidity control system according to claim 6where in an air washer is positioned in the airflow path between saiddust collector and said second area to provide a cooling effect on thecleansed air and to control the humidity thereof before the air enterssaid second area.

14. The temperature and humidity control system according to claim 6wherein the means connecting said heat reclaimer, makeup unit, and saiddust collector with said first and second areas comprises a series ofconduits, the conduit connecting said second area and said heatreclaimer including a means for spraying water on the exterior surfacethereof during the summer months when said first and second areas arebeing cooled.

1. A method of providing year around air conditioning for amanufacturing plant having a first and second area wherein diversemanufacturing operations are being carried on with consequent diverseeffects on the temperature and or humidity and cleanliness of the airwithin said first and second areas, and wherein relatively large volumesof air are circulated, approximately one-half by volume of thecirculated air being exhausted from said first area and containing solidcontaminants and approximately one-half of the circulated air beingexhausted from said second area and containing fumous contaminants, saidmethod comprising the steps of: a. drawing atmospheric air into theplant air-conditioning system from outside the plant; b. pretreatingsaid incoming atmospheric air by subjecting said air to thermalengagement with fumous contaminated air exhausted from said second areawhile preventing actual mixing of the air masses whereby said incomingair is precooled in the summer and preheated in the winter; c.Delivering said incoming pretreated atmospheric air to said first areaand contaminating it with solid particles; d. thereafter exhausting thesolid contaminated air from said first area and cleansing it of saidsolid particles; e. delivering the cleansed air to said second area andcontaminating it with fumes; f. thereafter exhausting the fumouscontaminated air from said second area and delivering it into thermalengagement with said incoming air while preventing actual mixture of theair masses; and g. delivering said fumous contaminated air to theatmosphere.
 2. The method according to claim 1 wherein subsequent tostep (b) said pretreated incoming air is further subjected to amechanical heating operation in the winter and a mechanical coolingoperation in the summer, said heating and cooling operation furtherincludes subjecting said incoming air to a washing operation whereinsaid air becomes saturated prior to delivery to said first area.
 3. Themethod according to claim 1 wherein the fumous contaminated air isfurther passed over a coil in a heat rejection device subsequent to step(f) thus transferring heat from the air to the coil in the winter andtransferring heat from the coil to the air in the summer operation. 4.The method according to claim 1 wherein the cleansed air is washed in anair washer subsequent to step (d), so that the temperature is loweredand the humidity is elevated to a prescribed level.
 5. The methodaccording to claim 1 wherein during the summer months, the fumouscontaminated air exhausted from the second area is subjected to a waterspray prior to step (f) thereby lowering the temperature of the airprior to its thermal engagement with said incoming air, so that theincoming air is precooled to an even greater extent.
 6. A temperatureand humidity control for use in a manufacturing plant having a first andsecond area in which diverse manufacturing operations are bEing carriedon with consequent diverse effects on the temperature and or humidityand cleanliness of the air within said first and second areas, andwherein relatively large volumes of air are circulated, approximatelyone-half by volume of the circulated air being exhausted from said firstarea and containing solid contaminants and approximately one-half of thecirculated air being exhausted from said second area and containingfumous contaminants, said system comprising: a. a makeup unit includinga means for drawing in the outside air into said system and deliveringit to said first area; b. a heat exchanger positioned in said systembetween the intake of said outside air and said makeup unit, said heatexchanger including a first means for passing said incoming airtherethrough, said heat exchanger further including a second means forpassing the fumous contaminated air exhausted from said second areatherethrough, said first and second means being separated by a wall ofheat conductive material, whereby heat is transferred between saidincoming air and said fumous contaminated air while preventing actualmixing of the air masses; c. a dust collector positioned in the systembetween said first and second areas and receiving the solid contaminatedair exhausted from said first area, said dust collector including ameans therein for separating the solid particles present in said solidcontaminated air from the clean air in preparation for the delivery ofthe cleansed air to said second area; and d. means connecting said heatreclaimer, makeup unit, and said dust collector with said first andsecond areas for providing an airflow path through said system.
 7. Thetemperature and humidity control system according to claim 6 whereinsaid first means in said heat exchanger comprises a first set ofpassageways therethrough in one direction through which the incoming airpasses and said second means in said heat exchanger comprises a secondset of passageways extending transversely to and in alternating relationwith said first set of passageways through which said fumouscontaminated air passes, said first and second passageways beingseparated by a relatively thin sheet of heat conductive material.
 8. Thetemperature and humidity control system according to claim 7 whereinsaid first and second passageways include at least one support memberextending between and in engagement with adjacent surfaces of said thinsheets of heat conductive material, said supports including a strip ofvibration absorbing material attached to the surfaces of said supportwhich engage said thin sheets.
 9. The temperature and humidity controlsystem according to claim 6 wherein said makeup unit further comprises amechanical heating/cooling unit for cooling said incoming air in summermonths and heating said incoming air in the winter months.
 10. Thetemperature and humidity control system according to claim 9 whereinsaid heating/cooling unit further comprising a compressor, a spray coilconnected to one side of said compressor and over which said incomingair passes, said coil receiving cooling media in the summer and heatingmedia in the winter, a condenser coil connecting said spray coil and theother side of said compressor.
 11. The temperature and humidity controlsystem according to claim 10 wherein said spray coil is enclosed withina housing through which said incoming air passes, said housing includinga means for increasing the moisture content of said incoming air. 12.The temperature and humidity control system according to claim 10wherein said condenser coil is enclosed in a housing through which thefumous contaminated air leaving said heat exchanger passes, whereby heatis transferred between the condenser coil and the air passingtherethrough.
 13. The temperature and humidity control system accordingto claim 6 where in an air washer is positioned in the airflow pathbetween said dust collector and said second area to provide a coolinGeffect on the cleansed air and to control the humidity thereof beforethe air enters said second area.
 14. The temperature and humiditycontrol system according to claim 6 wherein the means connecting saidheat reclaimer, makeup unit, and said dust collector with said first andsecond areas comprises a series of conduits, the conduit connecting saidsecond area and said heat reclaimer including a means for spraying wateron the exterior surface thereof during the summer months when said firstand second areas are being cooled.